Casement window locking systems are customarily riveted assemblies which are secured to the window frame jamb with screws in an exposed manner. The Rolscreen Company of Pella Iowa has used a one piece cam and handle locking system that is secured to and contained within the window frame jamb. A partially exposed locking system has been used wherein the handle was secured with a set screw to a splined stud attached to the concealed locking cam. Loosening of the set screw would allow accidental removal of the handle rendering the window unsafe if it was needed to open it in an emergency.
Whether the locking system is on the exterior of the frame jamb or contained within it, the handle or lever must be in place to operate the lock to hold the sash closed during building construction and finishing, including the finishing of the window.
A locking system is needed that will allow the installation of the exposed portions of the locking mechanism after finishing is completed. The locking system should provide for interchangeability of handles for purposes of color coordinating with interior room decorating at any time after the window is manufactured and installed.